Hyundai i20 Alternator: Specs, Fitment & Common Faults
On the i20, resting and running voltage figures genuinely reveal whether the alternator is charging correctly.
Illustration for editorial purposes
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OEM Part Number: 37300-2A950 (as quoted in catalogue listings — confirm via VIN) — aftermarket alternators Bosch 0 986 086 620 / Valeo 443239
| Alternators (aftermarket) | Bosch 0 986 086 620 (130 A, 5 ribs, 57 mm, reman exchange, plug 174, double pivot mounting, 179 mm long, excludes vacuum pump, core charge GBP 25.80); Bosch 1 986 A01 715 (130 A, 5 ribs, 57 mm, new, plug 174, double pivot mounting, 179 mm long, excludes vacuum pump, core charge GBP 7.31); Valeo 443239 (90 A, V-ribbed pulley, 5 ribs, 58 mm, new, three-point mounting); Valeo 616110 (90 A, V-ribbed pulley, new); AS-PL A9381S (120 A, freewheel clutch pulley, 5 ribs, 57 mm, new, PL_2305 plug); AS-PL A3805S (130 A, freewheel clutch pulley, 6 ribs, 55 mm, new, PL_3307 plug); AS-PL A3515S (90 A, rigid belt pulley, 5 ribs, 57.5 mm, new, PL_3307 plug); AS-PL A3530S (90 A, freewheel clutch pulley, 5 ribs, 57.5 mm, new, PL_3307 plug) |
|---|---|
| Outputs & variants | Outputs are 90 A, 120 A and 130 A. The 1.2 and 1.4 MPi petrols take the 90 A five-rib unit on a 57 to 58 mm pulley in rigid or freewheel form; the 1.0 T-GDi and higher-spec cars take 120 A or 130 A units, mostly freewheel clutch pulley with five, six or seven ribs; the 1.1 and 1.4 CRDi diesels sit at the 130 A end. |
| Genuine (OE) numbers quoted | AS-PL A9381S quotes 37300-2A950; AS-PL A3515S quotes 37300-03350; AS-PL A3530S quotes 37300-03600; AS-PL A3805S quotes 2616636; AS-PL A9443S quotes 37300-03815. |
| Fitment notes | Pulley rib count ranges from five to seven on this car and the 130 A units come on 55 mm, 57 mm or 58 mm pulleys, so match the old part carefully; Bosch, Walker and Rotovis exchange units carry refundable core charges; both Bosch units exclude engines with an alternator-driven vacuum pump and Bosch recommends renewing the belt. |
A Genuinely Useful Diagnostic Benchmark Worth Knowing — Hyundai i20 Alternator
If you're trying to determine whether the alternator is genuinely at fault, this is worth knowing: with the engine off, battery voltage should read between roughly 12.4 and 12.7 volts. Once started, this should rise to between roughly 13.7 and 14.7 volts if charging correctly. If a warning light appears while driving, turning off every accessory you safely can and seeing if the warning clears tells you whether there's still enough charging capacity to get you somewhere safely.
It's also worth knowing that on some models, the fuse protecting the alternator circuit isn't a conventional, easily replaceable fuse at all, but a shunt in a different physical location.
Hyundai i20 Alternator: Often Blamed on the Battery Instead
Early on, a weak Hyundai i20 battery and a dying alternator look almost identical — dim lights, sluggish starts, a car that won't hold its charge — which is exactly why so many people fit a new battery and end up back at the garage weeks later, the actual fault still unaddressed.
Hyundai i20 Alternator: Watch: Replacing It
Indian-market i20 CRDi; generation not stated in title, verify before linking
Hyundai i20 Alternator: What It Does
On the Hyundai i20, while the engine runs, the alternator generates the electricity that charges the battery and powers the car's electrical systems directly. With a healthy alternator, the battery's real job becomes starting the engine and covering brief demand spikes, rather than running the electronics on its own.
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Hyundai i20 Alternator: Warning Signs, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Alternator Guide for symptoms to watch for (plus a genuinely useful two-minute test to confirm it's not the battery instead), confirming the right amperage and fitment against your VIN, and which brands are worth trusting.
More Hyundai Alternator
The same part, covered across other Hyundai models.